Several devices have been invented for the purpose of amplifying a stringed musical instrument. These signal sensing devices, called pickups, convert either the wave motion of the vibrating string when played or the oscillating electrical field generated by a vibrating metallic string in a magnetic field into an electrical signal which can be amplified electrically.
The first type, called a transducer, is simply a miniature microphone which converts either the vibration of the air beneath the moving string or the vibrations within the material of the instrument into an electrical signal. This signal is then transmitted to the amplifier or signal processor by wire or by a radio transmitter.
The other common form of pickup is essentially a radio antenna. Beneath the set of strings to be amplified is a magnet or pair of magnets wrapped in loops of wire. When a metallic string vibrates above and within the magnetic field this induces an oscillating electrical field in the loops of wire and this electrical signal can also be sent by wire or radio to an amplifier for amplification.
These devices share the following characteristics: They are placed beneath the strings and the top surface of the instrument, usually between the fingerboard and the bridge of the instrument, in some cases they are attached directly to the bridge itself and the instrument may have to be physically altered to install the device.
The output of these devices is a composite of the various pitches produced by one or more strings as the string(s) vibrate, that is , the signal which ultimately gets amplified or processed arrives at the amplifier or processor as one discrete sound or signal.
These devices are stationary. Once installed, repositioning may be viewed as re-installing. Some manufacturers even specify the relative position between the fingerboard and bridge for which their pickup has been designed. There is no independent positioning on a per-string basis, that is, to exploit the tonal characteristics of another point on one string requires repositioning the pickup. Since all of the strings have different tonal characteristics at any given point, exploiting the desired tone of one string requires that the same position along the length of the entire stringset be exploited as well without regard to whether or not the other tones are desired. Traditionally, the only way to address this fact is to install one or more additional pickups at other lengths along the stringset and to use an electrical switch to activate/deactivate other pickups.
The linearly-positional, multi-configurational stringed musical instrument pickup (hereafter referred to as "pickup" or "mechanism") differs from the pickups described above as detailed in the Summary section of this application.